[nsp] Catalyst 4507R LAN Edge Routing (BGP)

[warner at cats.ucsc.edu]

In response to a request for info relevant to the subject line,
Shmapty said:

>I've got both 6000/s2's and 4000/s3's in this role. The performance of the 
>sup3 has been fantastic. The one major caveat to watch out for is the 128k fib 
>entry limitation -- with a full bgp feed, that should leave you with 
>approximately 10% free (and this is relatively static), but could leave you in 
>a bind if a provider hoses things and massively deaggregates.

I took a look at http://bgp.potaroo.net/as4637

A linear extrapolation of the prefix growth curve suggests that the
10 percent free margin (relative to 128K max fib size) will be gone
in a few months.  I don't see how anyone could look at the graph
and call it "relatively static."

What happens when the fib attempts to exceed 128K?  Surely this has
been tested by someone.  

Thanks.  -jim warner, UC Santa Cruz